Golden hood gardener
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Golden hood gardener ( Amblyornis macgregoriae ) |
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| Amblyornis macgregoriae | ||||||||||||
| De Vis , 1890 |
The golden hood gardener ( Amblyornis macgregoriae ) or yellow hood gardener is a species from the family of bower birds (Ptilonorhynchidae) and is a representative of the avifauna of New Guinea. Compared to the Chlamydera species found in Australia or the silky arboreal bird , this species, belonging to the genus Amblyornis, has been relatively little researched due to its poorly accessible distribution area.
With a body length of up to 26 centimeters, the golden hood gardener is one of the smaller representatives in the bowerbird family and is roughly the size of a thrush. It is one of the species whose courtship behavior includes the construction of an arbor by the male. There are several subspecies for this species. The golden hood gardener was first described in 1890 by the British ornithologist Charles Walter De Vis . It bears its specific epithet macgregoriae in honor of Sir William MacGregor, the first governor of the colony of British New Guinea .
Golden hood gardeners are very long-lived and take several years to reach sexual maturity. Due to the intelligence they show when building their arbors, they are counted among the most intelligent of the birds. According to the IUCN, their stock situation is classified as safe ( least concern ).
features
Appearance
The golden hood gardener reaches a body length of up to 26 centimeters, of which 7.8 to 9.2 centimeters are accounted for by the tail in the nominate form. The beak length is 2.7 to 3 centimeters. You reach a body weight between 100 and 145 grams.
In the male, the top of the body is a dark olive color. The face and neck are a little lighter, the parting is tinged with orange-red. The coat and the tail plumage are slightly darker than the rest of the upper body. Some feathers are elongated on the back of the head and on the upper neck and have a shiny metallic orange color. With certain incidence of light, white highlights form on these feathers.
The underside of the body is dark ocher, the sides of the chest and the flanks are a little darker, the chin and throat a little lighter. The iris is dark brown, the beak is blackish with a blue beak base. The legs and feet are dark gray.
The female resembles the male, but lacks the orange-red feathers. The plumage shimmers slightly orange on the coat, crown and trunk as well as on the neck. Males not yet sexually mature are similar to males, but they show the first signs of the forming feathers in the neck. Male juveniles are a little more brownish compared to the females.
voice
The golden hood gardener has a very large repertoire of voices. As is typical for most species of bowerbird, it imitates the calls of a number of bird species in its habitat as well as the sounds of its surroundings. Among other things, with his voice he also imitates the fluttering of wings that males consciously produce as an instrumental sound near their arbor . HE also mimics sounds like falling trees and the murmur of distant human conversation.
The mimicked birdcalls of its surroundings include the crackling noises of the narrow-tailed paradise hop ( Epimachus meyeri )
Distribution area and subspecies
The golden hood gardener is a shy bird, although it is quite common in its area of distribution. There are seven subspecies that are native to western New Guinea west of the Weyland Mountains and in Papua New Guinea in the Adelbert Mountains, the Huon Peninsula and Mount Bosavi at an altitude of 1600 to 3300 m above sea level. The Vogelkop , the peninsula in western New Guinea , is not populated .
The following subspecies are distinguished:
- At the. macgregoriae - De Vis, 1890 - Southeast New Guinea
- At the. mayri - EJO Hartert, 1930 - West and Central Area of New Guinea. The distribution area includes the Weyland Mountains and the west of the Hindenburg Mountains.
- At the. lecroyae - CB Frith & DW Frith, 1997 - Distribution area is the mountain range of Mount Bosavi
- At the. kombok - Schodde & McKean, 1973 - East New Guinea, The range includes the Kraetkegebirge and the Bismarckgebirge
- At the. amati - TK Pratt, 1982 - Adelbert Mountains in northeast New Guinea
- At the. germana - Rothschild, 1910 - Mountains of the Huon Peninsula in northeast New Guinea.
- At the. nubicola - Schodde & McKean, 1973 - extreme southeast of New Guinea. The Owen Stanley Mountains belong to the distribution area .
The golden hood gardener's habitat are mountain forests. It only occurs in primary forest. The distribution area of the golden hood gardener partially overlaps that of the red hood gardener , which occurs at lower altitudes. Clifford and Dawn Frith consider it possible that the red-hood gardener was displaced to lower altitudes by the more common gold-hood gardener - who is slightly larger with a body length of up to 26 centimeters. From their point of view, the more complexly built arbor may also be the result of a stronger separation of the two species from one another.
food
The golden hood gardener mainly eats fruits from various trees, shrubs and climbing plants. It also eats flowers and occasionally insects. The fruits eaten have a diameter of up to 2.4 centimeters. In individual research areas, up to 130 different plant species were found that are used by the golden hood gardener. Fruits are usually eaten on the spot immediately. Males owning arbor, on the other hand, also hoard fruit, a behavior that is also known from arborebirds of the genus Ailuroedus and from column gardeners .
Some tree species, which play a particularly important role in the diet of the golden hood gardener, are most often found on ridges or in the upper part of slopes. Most of the arbors built by the males are located in these places. Males that build their arbors near these trees do not need to stray too far from their arbors while foraging, and they are better able to attract females than elsewhere.
Golden hood gardeners look for food alone or in small groups. Adult males can often be observed together with subadult males in the treetops. In the adult males it has not yet been found that they are defending their food sources against other birds. On Mount Besavi, 7 of the 8 golden arboretum birds caught were caught with traps that were actually set up for mammals living on the ground. This indicates that gold hood gardeners also pursue part of their foraging on the ground.
Reproduction
The males of the golden hood gardener are polygyn , that is, they mate with several females. The female builds the nest alone, incubates the clutch alone and raises the young birds alone. The males woo the females by building arbors, which, like the column gardener and the other Amblyornis species, belong to the "maypole" type. Compared to the cottage gardener, the arbor of the golden hood gardener, together with that of the yellow-crowned gardener, is one of the comparatively simple constructions.
The locations of the maypoles are often used over several years. In the case of a maypole, it is assumed that it was continuously occupied for more than 20 years.
Location of the maypole
The gold hood gardener's individual maypoles are no more than 200 meters apart. The locations are not chosen at random. The males show a clearly demonstrable preference for slope crests or slopes with a certain inclination. Other influencing factors are the canopy density of the surrounding trees and the number of tree sprouts in the vicinity. Of 46 maypoles examined, 40 stood directly on a ridge and six more were three to 30 meters away from the ridge.
Maypole and moss platform
A total of five species of bowerbirds build an arbor of the maypole type. It is a construction in which branches are joined around a thinner tree trunk or a tree fern. The resulting column of twigs around this trunk is the essential characteristic of this type of arbor.
The golden hood gardener builds the simplest form of this arbor. The biologist Hansell describes that the golden hood gardener's maypole is only two or three times the height of the male's body and consists of a few hundred fine knots in the center of an otherwise unadorned moss platform. He also states that the arbor is not decorated.
According to Clifford and Dawn Frith, the golden hood gardener's maypole is between 30 centimeters and 3 meters high. The diameter of the maypole is between 20 and 50 centimeters. It is erected on a slender tree trunk (alternatively a tree fern) that is one to five meters high. The moss platform around the maypole has a diameter of about one meter. It is closed off by a raised edge of moss that is about 22 centimeters wide and 5 to 75 centimeters higher than the moss platform.
Jewellery
While Hansell describes the building of the golden hood gardener as unadorned, Clifford and Dawn Frith name the following decorative elements: rust-red insect excreta , coal, mushrooms, tree wax, dung from mammals, small fruits, lichens, flowers, leaves, including the large leaves of screw pines , wing cases of insects and butterfly wings. Man-made things are also placed near the maypole by the males of the golden hood gardener. In the case of the golden bonnet gardeners found in the remote mountain forests of New Guinea, however, this does not play such a large role as, for example, with the drip arborebird or the silky arborebird . The decorative objects are placed on the moss platform by the golden hood gardener and some of them are also hung in the lowest branches of the maypole. In individual cases, fruits are also placed on fallen tree trunks within a radius of up to three meters around the maypole.
The decorated cover wings come from beetles that were previously eaten by the golden hood gardener. This behavior is described in all species of the genus Amblyornis as well as the Archbold bower bird .
A painting of the arbor, as it is described, for example, for the yellow-naped bowerbird, has not yet been observed in the golden crested bird . But one male chewed whitish leaves and then hung them on the ends of the branches from which the maypole was constructed.
Seasonality. Time investment and defense of the arbor
The males of the golden bonnet gardeners stay close to their arbor all year round. They build their arbor from the end of April to February of the next year. The start of the renewed construction activities on the arbor coincides with the start of the dry season. They are busy with the repairs until August, and they bring in jewelry objects mainly in the months of June to July. In October, when the rainy season starts again, they start courting. In the few weeks that they do not build the arbor, they go through the moult .
Five males, who were observed more intensively, spent an average of 54 percent of the day within a radius of 15 to 20 meters around the arbor. They also defended this area against other males. From the time they spend near the arbor, they sit in a raised hide at a distance of five to 10 meters without uttering any voices. They called 14 percent of the time. They spent 12 percent of their time mending the arbor and another three percent of the time they interacted with conspecifics approaching the arbor. Competing males visit the arbors comparatively frequently: of the 18 mating attempts observed, 39 were interrupted by competing males. Rival males try to damage the rival's arbor and steal jewelry objects as well as the moss that is piled up at the end of the maypole. In 20 observed rivals intruding into the immediate football field of a hood owner, the arbor was partially or completely destroyed in nine cases. The canopy owners spent anywhere from several minutes to five hours repairing the arbor.
Golden hood gardener males not only chase away competing males of their own species, but also other bird species up to the size of a large pigeon. In addition to pigeons, large foot fowl and birds of paradise were also chased away , including the black-eared bower bird .
Nest, brood and rearing of the young birds
The breeding season falls mainly in the months of October to January. The nest is built in the crowns of screw trees , tree ferns and tree sprouts. The height above the ground averages 2.3 meters. The nests are often at a distance of about 30 meters from an arbor. The nest is shaped like a bowl and is built on a loose platform from larger branches.
The clutches found each comprised a single egg. The eggshell was white with no other color markings. The full freshness weight was 19 grams, which is about 15.7 percent of the average weight of a female. One nestling that was weighed shortly after hatching weighed 20.5 grams. The female feeds the nestlings with fruits and insects such as singing cicadas and ants.
Trivia
In 1967 Heinz Sielmann published an approx. 4½-minute educational film about the courtship behavior of the golden hood gardener.
literature
- John Alcock: Animal behavior , from the American. by Matthias Sauerland, Gustav Fischer Verlag, 1996, ISBN 3-437-20531-5 , pp. 295 and 322
- Bruce M. Beehler, Thane K. Pratt: Birds of New Guinea; Distribution, Taxonomy, and Systematics . Princeton University Press, Princeton 2016, ISBN 978-0-691-16424-3 .
- Bruce M. Beehler: Birds of New Guinea , 1986
- Jared Diamond : The third chimpanzee . S. Fischer Verlag, Frankfurt am Main 1994, ISBN 3-596-17215-2 .
- Clifford B. Frith, Dawn. W. Frith: The Bowerbirds - Ptilonorhynchidae . Oxford University Press, Oxford 2004, ISBN 0-19-854844-3 .
- Mike Hansell: Bird nests and construction behavior , illustrated by Raith Overhill, Cambridge University Press, ISBN 0521017645 .
- Peter Rowland: Bowerbirds . Csiro Publishing, Collingwood 2008, ISBN 978-0-643-09420-8 .
Web links
- Macgregor's Bowerbird at www.answers.com (engl.)
- Amblyornis macgregoriae in the Red List of Threatened Species of the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 2 of 2009.
- Video: Heinz Sielmann: Amblyornis macgregoriae - hanging the "maypole" and courtship . Institute for Scientific Film (IWF) 1967, made available by the Technical Information Library (TIB), doi : 10.3203 / IWF / E-1083 .
Individual evidence
- ↑ a b c Handbook of the Birds of the World zum Goldhaubengärtnerl , accessed on April 14, 2017
- ↑ a b c d e Frith: The Bowerbirds - Ptilonorhynchidae . P. 280.
- ^ Beehler & Pratt: Birds of New Guinea . P. 277.
- ↑ Bo Beolens, Michael Watkins: Whose Bird ?: Common Bird Names and the People They Commemorate . Yale University Press, London 2004, ISBN 978-0300-10359-5 .
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 277.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 275.
- ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 276.
- ↑ a b c d Frith: The Bowerbirds - Ptilonorhynchidae . P. 279.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 289.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 278.
- ^ A b c Hansell: Bird nests and construction behavior . P. 195.
- ^ Hansell: Bird nests and construction behavior . P. 196.
- ↑ a b c d Frith: The Bowerbirds - Ptilonorhynchidae . P. 281.
- ↑ a b c Frith: The Bowerbirds - Ptilonorhynchidae . P. 282.
- ↑ a b Frith: The Bowerbirds - Ptilonorhynchidae . P. 285.
- ↑ Frith: The Bowerbirds - Ptilonorhynchidae . P. 283.
- ^ " Amblyornis macgregoriae (Ptilonorhynchidae) - hangings of the" maypole "and courtship " by Heinz Sielmann. IWF Knowledge and Media gGmbH, 1967